Semiconductor devices such as an LED and a power module have a structure in which a semiconductor element is bonded onto a circuit layer formed from a conductive material.
In a power semiconductor element for a large-power control used to control wind power generation, electric vehicles, hybrid cars, and the like, the amount of power generation is great. Accordingly, as a substrate on which the power semiconductor element is mounted, for example, a power module substrate which includes a ceramic substrate formed from aluminum nitride (AlN), alumina (Al2O3), and the like, and a circuit layer formed by arranging a metal having excellent conductivity and the like on one surface of the ceramic substrate has been widely used in the related art.
As the power module substrate, a substrate in which a metal layer is formed on the other surface of the ceramic substrate is also provided.
Here, when mounting the semiconductor element on the circuit layer, for example, a resin composition such as a conductive adhesive is used in some cases. The resin composition is cured with heat and the like, and thus bonding of a member and the like can be performed by curing the resin composition after applying the resin composition to a portion to be bonded. As the resin composition, typically, a resin composition including a binder resin and conductive particles is known.
For example, PTL 1 discloses a resin composition which uses a resin in which an epoxy resin is set as a main component as the binder resin, and silver particles as the conductive particles. In PTL 1, an epoxidized butadiene-styrene copolymer is additionally added as a resin binder to mitigate stress of an adhesive layer formed by curing the resin composition.
In addition, for example, PTL 2 discloses a resin composition which includes an epoxy compound as a binder resin, and in which a nickel powder or a silver-coated powder is used as the conductive particles. In PTL 2, as a catalyst that cures the binder resin, an organic metal complex of titanium or zirconium is used to suppress deterioration of conductivity due to a heat cycle.